net.sf.saxon.expr
Class Calculator

java.lang.Object
  net.sf.saxon.expr.Calculator

All Implemented Interfaces:

Serializable

public abstract class Calculator
extends Object
implements Serializable

This class evaluates arithmetic expressions; it acts as a helper class to the ArithmeticExpression class. There are many subclasses for the different kinds of arithmetic expression, and static methods that allow the right subclass to be selected, either at compile time or at run time.

See Also:

Serialized Form

Field Summary

static Calculator[]	ANY_ANY Calculators used for the six operators when the static type information does not allow a more specific calculator to be chosen
static Calculator[]	DATETIME_DATETIME Calculators used when both operands are xs:dateTime, xs:date, or xs:time
static Calculator[]	DATETIME_DURATION Calculators used when the first operand is xs:dateTime, xs:date, or xs:time, and the second is a duration
static Calculator[]	DECIMAL_DECIMAL
static Calculator[]	DECIMAL_DOUBLE Calculators used when the first operand is a decimal
static Calculator[]	DECIMAL_FLOAT
static Calculator[]	DECIMAL_INTEGER
static int	DIV
static Calculator[]	DOUBLE_DECIMAL
static Calculator[]	DOUBLE_DOUBLE Calculators used when the first operand is a double
static Calculator[]	DOUBLE_FLOAT
static Calculator[]	DOUBLE_INTEGER
static Calculator[]	DURATION_DATETIME Calculators used when the second operand is xs:dateTime, xs:date, or xs:time, and the first is a duration
static Calculator[]	DURATION_DURATION Calculators used when the both operands are durations
static Calculator[]	DURATION_NUMERIC Calculators used when the first operand is a duration and the second is numeric
static Calculator[]	FLOAT_DECIMAL
static Calculator[]	FLOAT_DOUBLE Calculators used when the first operand is a float
static Calculator[]	FLOAT_FLOAT
static Calculator[]	FLOAT_INTEGER
static int	IDIV
static Calculator[]	INTEGER_DECIMAL
static Calculator[]	INTEGER_DOUBLE Calculators used when the first operand is an integer
static Calculator[]	INTEGER_FLOAT
static Calculator[]	INTEGER_INTEGER
static int	MINUS
static int	MOD
static Calculator[]	NUMERIC_DURATION Calculators used when the second operand is a duration and the first is numeric
static int	PLUS
static int	TIMES

Constructor Summary

Calculator()

Method Summary

abstract AtomicValue	compute(AtomicValue a, AtomicValue b, XPathContext c) Perform an arithmetic operation
static Calculator	getCalculator(int typeA, int typeB, int operator, boolean mustResolve) Factory method to get a calculator for a given combination of types
static String	getCalculatorSetName(int typeA, int typeB) Get the name of the calculator set for a given combination of types
abstract AtomicType	getResultType(AtomicType typeA, AtomicType typeB) Get the type of the result of the calculator, given arguments types typeA and typeB

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

PLUS

public static final int PLUS

See Also:

Constant Field Values

MINUS

public static final int MINUS

See Also:

Constant Field Values

TIMES

public static final int TIMES

See Also:

Constant Field Values

DIV

public static final int DIV

See Also:

Constant Field Values

MOD

public static final int MOD

See Also:

Constant Field Values

IDIV

public static final int IDIV

See Also:

Constant Field Values

ANY_ANY

public static Calculator[] ANY_ANY

Calculators used for the six operators when the static type information does not allow a more specific calculator to be chosen

DOUBLE_DOUBLE

public static Calculator[] DOUBLE_DOUBLE

Calculators used when the first operand is a double

DOUBLE_FLOAT

public static Calculator[] DOUBLE_FLOAT

DOUBLE_DECIMAL

public static Calculator[] DOUBLE_DECIMAL

DOUBLE_INTEGER

public static Calculator[] DOUBLE_INTEGER

FLOAT_DOUBLE

public static Calculator[] FLOAT_DOUBLE

Calculators used when the first operand is a float

FLOAT_FLOAT

public static Calculator[] FLOAT_FLOAT

FLOAT_DECIMAL

public static Calculator[] FLOAT_DECIMAL

FLOAT_INTEGER

public static Calculator[] FLOAT_INTEGER

DECIMAL_DOUBLE

public static Calculator[] DECIMAL_DOUBLE

Calculators used when the first operand is a decimal

DECIMAL_FLOAT

public static Calculator[] DECIMAL_FLOAT

DECIMAL_DECIMAL

public static Calculator[] DECIMAL_DECIMAL

DECIMAL_INTEGER

public static Calculator[] DECIMAL_INTEGER

INTEGER_DOUBLE

public static Calculator[] INTEGER_DOUBLE

Calculators used when the first operand is an integer

INTEGER_FLOAT

public static Calculator[] INTEGER_FLOAT

INTEGER_DECIMAL

public static Calculator[] INTEGER_DECIMAL

INTEGER_INTEGER

public static Calculator[] INTEGER_INTEGER

DATETIME_DATETIME

public static Calculator[] DATETIME_DATETIME

Calculators used when both operands are xs:dateTime, xs:date, or xs:time

DATETIME_DURATION

public static Calculator[] DATETIME_DURATION

Calculators used when the first operand is xs:dateTime, xs:date, or xs:time, and the second is a duration

DURATION_DATETIME

public static Calculator[] DURATION_DATETIME

Calculators used when the second operand is xs:dateTime, xs:date, or xs:time, and the first is a duration

DURATION_DURATION

public static Calculator[] DURATION_DURATION

Calculators used when the both operands are durations

DURATION_NUMERIC

public static Calculator[] DURATION_NUMERIC

Calculators used when the first operand is a duration and the second is numeric

NUMERIC_DURATION

public static Calculator[] NUMERIC_DURATION

Calculators used when the second operand is a duration and the first is numeric

Constructor Detail

Calculator

public Calculator()

Method Detail

getCalculator

public static Calculator getCalculator(int typeA,
                                       int typeB,
                                       int operator,
                                       boolean mustResolve)

Factory method to get a calculator for a given combination of types

Parameters:

typeA - fingerprint of the primitive type of the first operand

typeB - fingerprint of the primitive type of the second operand

operator - the arithmetic operator in use

mustResolve - indicates that a concrete Calculator is required (rather than an ANY_ANY calculator which needs to be further resolved at run-time)

Returns:

null if no suitable Calculator can be found.

getCalculatorSetName

public static String getCalculatorSetName(int typeA,
                                          int typeB)

Get the name of the calculator set for a given combination of types

Parameters:

typeA - the fingerprint of the primitive type of the first operand

typeB - the fingerprint of the primitive type of the second operand

Returns:

null if no suitable Calculator can be found.

compute

public abstract AtomicValue compute(AtomicValue a,
                                    AtomicValue b,
                                    XPathContext c)
                             throws XPathException

Perform an arithmetic operation

Parameters:

a - the first operand. Must not be null, and must be an instance of the type implied by the class name.

b - the second operand. Must not be null, and must be an instance of the type implied by the class name.

c - the XPath dynamic evaluation context

Returns:

the result of the computation, as a value of the correct primitive type

Throws:

XPathException - in the event of an arithmetic error

getResultType

public abstract AtomicType getResultType(AtomicType typeA,
                                         AtomicType typeB)

Get the type of the result of the calculator, given arguments types typeA and typeB

Parameters:

typeA - the type of the first operand

typeB - the type of the second operand

Returns:

the type of the result